Grain-to-Gain: Comparing the impact of wheat varieties and agricultural practices on sourdough microbiomes

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Commodities

• Agronomic: wheat

Practices

• Crop Production: food product quality/safety, varieties and cultivars
• Education and Training: extension, youth education
• Natural Resources/Environment: biodiversity
• Production Systems: organic agriculture
• Sustainable Communities: local and regional food systems

Wheat is a staple crop globally and one of the five most valuable
crops in Pennsylvania. Wheat is milled into flour to produce
staple foods like bread and baked products. Studies investigated
the microbial diversity of wheat and bread products including
sourdough. However, the changes of microbial diversity from wheat
to flour to bread remains less understood. I propose to
investigate the influence of wheat varieties, farming methods,
and processing techniques in a sourdough model system. By
tracking biodiversity changes from farm-to-fermentation, I seek
to use this ancient knowledge to modernize wheat-based products.

Ancient and common wheat will be grown under organic or
conventional farming. Amplicon sequencing of wheat berries will
determine diversity and abundance of bacteria and fungi. Whole
wheat and refined grain flours will be produced from the
different wheat and farming methods. Flour from ancient v. modern
wheat, organic v. conventional, and whole v. refined will be
sequenced and utilized to create sourdough starters. Comparative
physical and chemical analysis of starters will include organic
acids, pH, and free amino acids. Mature sourdoughs will be
sequenced. Outcomes from this study could provide insights into
preservation and resilience of microbial communities from
farm-to-fermentation.

This proposed work aligns with our current USDA NIFA funded
project (#2023-67017-40251) that characterizes sourdough
microbiomes to enhance quality and nutrition of breads. The
proposed study seeks to conserve biodiversity in locally produced
staple crops, including ancient wheat, which offers opportunities
for market expansion. This research supports local farmers and
consumers, promoting sustainable agriculture within Pennsylvania.

Objective 1: Compare microbial diversity between
common wheat (T. aestivum) and ancient wheat (T.
monococcum) farmed conventionally and organically in
Pennsylvania. I hypothesize that ancient and common wheat will
have significantly different microbial diversity. I also
hypothesize that organically farmed grains will have higher alpha
diversity. Overall, I hypothesize that ancient wheat grown
organically will have the highest alpha diversity. Beta diversity
is expected to be high between samples. This objective will
result in tables with relative abundance of bacteria and fungi
and results of statistical analyses of microbial diversity.

Objective 2:

(2a) Assess microbial diversity in whole-grain
and refined grain flours derived from common wheat (T.
aestivum) and ancient wheat (T. monococcum) farmed
organically and conventionally in Pennsylvania.

(2b) Utilize flours from 2a to develop and
characterize sourdough starter cultures and evaluate their
functional outcomes. I hypothesize that whole wheat flour will
have a higher alpha diversity than refined grain flour. I also
hypothesize that ancient wheat grown organically and milled into
whole wheat flour will produce sourdough starters with the lowest
pH, highest organic acids, and highest microbial alpha diversity.
Beta diversity is expected to be high between samples. This
objective will result in tables with relative abundance of
bacteria and fungi, statistical analyses of microbial diversity
and proximate analysis measurements, and graphs illustrating
sourdough proximate analysis results.